Direct Measurement of Black Hole Jet Power Rewrites Galaxy Formation Models
Astronomers used 18 years of global radio observations to directly measure the power of jets from Cygnus X-1, a black hole–supergiant binary, finding the jets carry energy equivalent to about 10,000 suns and travel at ~150,000 km/s, with winds deflecting them by ~2 degrees. This instantaneous jet-power reading links accretion to ejection, confirms a long-standing 10% energy-into-jets assumption in galaxy-formation simulations, and provides a scalable anchor for calibrating jet power across black-hole masses as next-generation telescopes come online.